Pathak, PurnimaKASHYAP, SRISHTTY2024-07-112024-07-112023https://krishikosh.egranth.ac.in/handle/1/5810211789Assam lemon, commonly known as “Kaji nemu” is an indigenous pride fruit of Assam. Due to the state's favorable climate, Assam lemons are readily available all round the year, with production peaking from April -September. This causes a market oversupply, which drives down the market price. Due to their physiological weight loss, these fruits are difficult store for an extended period. Moreover, fresh quality degrades along with the decrease in juice content across the storage. Therefore, focusing on juice processing Assam lemon fruit may assist to to prevent losses incurred by citrus growers as a result of the aforementioned issues. Based on this concept, the present investigation was framed and carried out to evaluate the shelf life of the processed Assam lemon juices in response to various treatments and to find out the economics of their preparation and preservation. Eight different treatments were prepared in matured (90-110 DAFS) and ripe (120-150 DAFS) lemon juices. Among the eight treatments T1 and T2 were untreated matured and ripe juice whereas T3, and T4 were treated with KMS. T5 and T6 were pasteurized and T7 and T8 were preserved by a combination of KMS and pasteurization in both matured and ripe juices, respectively. All the treatments were stored in refrigerated condition. The evaluation of the physico-chemical and sensory parameters was carried out for 180 days at intervals of 30 days while the microbial evaluation was carried out at intervals of 15 days. Regarding physico-chemical changes during storage of the Assam lemon fruit juices, samples T7 and T8 showed better results for TSS and titrable acidity which kept on increasing throughout the storage period whereas the pH and ascorbic acid kept decreasing. It was noticed that T8 had higher TSS and titratable acidity but lower pH and ascorbic acid content than that T7. The highest scores for overall acceptability, colour, mouthfeel, and taste were recorded in treatment T8 followed by T7 which showed means higher than the global mean on the initial day. The untreated, KMS-treated, as well as solely pasteurized juices, were discarded after 90, 120, and 150 days respectively after they crossed the microbial permissible limit. Highest B: C ratio was observed in treatment T2 (2.18) followed by T4 (2.16) as they had comparatively lesser treatment expenses. However, after considering the shelf life of the above treatments, they only persisted for 90 and 120 days, respectively. Interestingly, T8 had a B: C ratio of 1.78 but remained consumable for 180 days. Hence, it might be safe to establish that treatment T8 resulted in the highest shelf life with better retention of the physico-chemical and sensory parameters maintaining a decent B: C ratio. The investigation recommends that ripe Assam lemon juices given combined heat and chemical treatment can be effectively used to develop commercial Assam lemon juices with acceptable flavour and quality attributes.EnglishThesis